Two or more semiconductor chips (dies) are often integrated in the same package, e.g., in the case of a power transistor die and a driver die, a sensor die and a controller die, etc. Some conventional multi-chip packaging solutions use multiple PCBs (printed circuit boards) to stack chips, which increases overall packaging cost. Chip stacking also has increased manufacturing complexity. For example, a high precision wire bond technique may be needed which is costly. Also, the likelihood of chip damage increases due to the complex manufacturing process. Other conventional solutions use chip embedding. Chip embedding also is complex, and involves a serial manufacturing process. Chip embedding offers no flexibility in chip variation once a chip is fixed in place. Chip embedding may suffer from artificially high yield loss since a good chip will be lost if a faulty package cannot be reworked.
Some package solutions require a cavity, e.g., in the case of a MEMS (microelectromechanical systems) sensor solution. The membrane of a MEMS sensor should not be contacted by the encapsulation material for the package. A metal lid may be used to cover and protect the MEMS sensor, but increases package height. A Si lid may instead be attached by silicone to cover and protect the MEMS sensor, but increases package cost. Silicone glue may instead be used to cover and protect the MEMS sensor, but may bleed which is hard to control.
Thus, there is a need for improved chip-packages.